diff --git a/libc/stdio/vfprintf.cpp b/libc/stdio/vfprintf.cpp
index 7a67868..a14963e 100644
--- a/libc/stdio/vfprintf.cpp
+++ b/libc/stdio/vfprintf.cpp
@@ -206,7 +206,7 @@
         if (width >= 0) goto rflag;
         if (width == INT_MIN) goto overflow;
         width = -width;
-        /* FALLTHROUGH */
+        __BIONIC_FALLTHROUGH;
       case '-':
         flags |= LADJUST;
         goto rflag;
@@ -305,7 +305,7 @@
         goto rflag;
       case 'C':
         flags |= LONGINT;
-        /*FALLTHROUGH*/
+        __BIONIC_FALLTHROUGH;
       case 'c':
         if (flags & LONGINT) {
           mbstate_t mbs;
@@ -327,7 +327,7 @@
         break;
       case 'D':
         flags |= LONGINT;
-        /*FALLTHROUGH*/
+        __BIONIC_FALLTHROUGH;
       case 'd':
       case 'i':
         _umax = SARG();
@@ -453,7 +453,7 @@
         __fortify_fatal("%%n not allowed on Android");
       case 'O':
         flags |= LONGINT;
-        /*FALLTHROUGH*/
+        __BIONIC_FALLTHROUGH;
       case 'o':
         _umax = UARG();
         base = OCT;
@@ -473,7 +473,7 @@
         goto nosign;
       case 'S':
         flags |= LONGINT;
-        /*FALLTHROUGH*/
+        __BIONIC_FALLTHROUGH;
       case 's':
         if (flags & LONGINT) {
           wchar_t* wcp;
@@ -505,7 +505,7 @@
         break;
       case 'U':
         flags |= LONGINT;
-        /*FALLTHROUGH*/
+        __BIONIC_FALLTHROUGH;
       case 'u':
         _umax = UARG();
         base = DEC;